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domingo, 27 de dezembro de 2009

Epigenetics and the Passing of Acquired Traits to Offspring

The same year that celebrated Charles Darwin witnessed numerous reports that give a measure of credence to a scientist historically viewed as his competitor: French biologist John-Baptiste Lamarck. In the early 19th century Lamarck asserted that acquired characteristics can be transmitted to offspring. In this tradition, the science of epigenetics, which studies the ways genes are switched on through environmental influences (and can remain in that state over multiple generations) experienced a banner year.
In February researchers reported in The Journal of Neuroscience that exercise, social interactions and other forms of stimulation enhanced brain activity that promotes learning and memory in mice genetically engineered to have memory deficits. Offspring of these mice, moreover, experienced improved cognition through early adolescence.
A November report in the journal Endocrinology showed that the pups of pregnant mice fed a high-fat diet during pregnancy were longer than normal and insensitive to the effects of insulin, a trait that persisted into a subsequent generation.
Such persistent epigenetic changes are likely to apply to humans. Researchers have been studying how chemicals in the environment can alter epigenetic switches in our bodies and leave us vulnerable to diseases ranging from diabetes to cancer.

In "Scientic American"

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